Fan balancing means



A ril 25, 1967 v. N. DELANEY FAN BALANCING MEANS Filed April 18, 1966 Q M 0% a m e D M w v.n VIB "Tliis -iav'ehaenrrerates and deals more articularly with improvements blade assemblisi i i'if a .aTheegnerdlsobject thedn ntion; o5. blade assembly including balancing means which ma p ly and accurately afiixed tethie asset-ti ae A further object 'nv ent ionls to TOVldC a fan blade assent-e13 that may he ieadilybala N versely affecting the appeaiance'tof th ssemblyP ix JOthe'rTobjectsand.advantagesifif thfiimtenti r fo minga partt ereat. 1:: T t-\i. i .t-

y r F The drawing shows a preferred embodiment he 1ns'paeed; elationat otthr lrub portio ofi tlie x vention \aaaisus witht etqeg ripqqspage illustrated em'bodimentbfi the in ntioif ea -blade' 1'8' has' Will be nd o that Varioll changes 3 be made fro art-substantially;iflattcentral' iportiona whichriests-tuporr andg t c ns C i diSClOS-dy d tfie d fi gt which isrriye'tecliitorstheafrorit surfaces ofr-anias's-ociatedepairs scription are not to be construed as defining or limiting f flanges 23, 28 the Scope of the invention, the claims forming a P Of At this point it should be noted that when the blades this Specification being Telied p for that 'P 'P have been attached to the arms in the aforedescribed man- Of the drawing: ner, each blade 18, the web section 26 and the transitional FIG. 1 is a fragmentary rear view of a balanced fan sections 30, associated therewith define a radially outassembly embodying the present invention. wardly opening channel 38 behind the blade as best shown FIG. 2 is a fragmentary side view of the fan assembly 30 i FIG, 2, of FIG. 1. After a hub and blades have been attached to a spider FIG. 3 is a fragmentary sectional view taken along the it is essential that the resulting assembly be properly balline 33 of FIG. 1. anced for vibration free rotation to insure smooth fan FIG. 4 is a front view of the balance clip shown in operational characteristics and it is for this purpose that FIG. 1. the balance clip 20 is provided. The balance characteristic FIG. 5 is a side view of the balance clip of FIG. 4. of the aforedescribed assembly is determined by aconven- Referring particularly to FIG. 1 of the drawing, a fan tional balancing means well known to those skilled in the blade assembly embodying the invention and indicated art. Thereafter one or more clips are slidably positioned generally at 10 is shown to comprise a spider 12 having a on one or more of the web sections 26, 26 to attain a central or hub portion 14 and including a plurality of desired balanced condition. radially outwardly extending circumaxially spaced arm The clip may be made from various materials and in portions 16, 16 which provide support for a plurality of various forms and weights to compensate for various outf bl d 18, 18, of-balance conditions. Preferably, the clip is formed in a In accordance with the present invention each of the generally U-shaped configuration from a resilient material arm portions or arms 16 is provided with a web section such as flat spring metal and is adapted to straddle an which is spaced from an associated blade 18 carried by the associated Web section.

arm and balance of the fan assembly 10 is achieved by at Considering now the clip in further detail and referring least one balance clip 20 which is slidably received on an particularly to FIGS. 3, 4 and 5 it will be observed that associated web section. A retaining means is also prothe clip 20 includes a generally U-shaped inwardly openvided for holding the clip 20 in assembled relationship ing outer end portion 40 which is adapted to engage the with the other parts of blade assembly 10 so as to resist outer edge 32 of the web section 26. Two elongated legs separation therefrom under normal fan operational condi- 42 and 44 converge generally inwardly from the end portions. tion 40 to springingly engage opposite sides of the web The spider 12 is preferably formed of sheet metal in a section 26 when the clip 20 is positioned thereon as best series of blanking and forming operations and includes an shown in FIG. 3. Free end portions 46 and 48 of the optional number of arms 16, 16. The hub portion 14 is 00 respectively associated legs 42 and 44 curve arcuately preferably apertured for convenient attachment to a hub outwardly or away from the web section 26 to define an rotatable on an axis 22 and for this purpose a C ntr l open end 50 which is substantially wider than the thickp 24i$ ShOWIl- Provision is made for Suitably P ness of the web 26. The divergent arrangement of the ing the fan blades 18, 18 and each of the arms 16, 16 is angularly displaced or twisted about a radial centerline such as 25 with respect to the aforesaid hub portion 14.

The configuration of the arms 16, 16 may vary but preferably and as shown each of the arms includes a relazfi ifig :28 2 22;}: 22 g it g i g zg ig g tively wide substantially flat radially outwardly extending 65 52 h l y 8 e m central zone or web section 26 and a pair of relatively as a genera 1y rectangular configuranon and 1S Struck end portions 46 and 48 serves to guide the clip 20 for rapid sliding assembly with the web 26.

A tab 52 formed on one of the legs is adapted to narrow substantially flat opposite side marginal portions from 44 and to an inclined Position relative or flanges 28, 28 each of which is offset forwardly with to the Sald leg to Prolect ge nerany toward the other leg respect to an associated web section 26. The flanges 28, 42 toward the end Portlon The lab 52 d s 28 associated with each of the arms 16 lie substantially in an outwardly facing end Portion 54 which engages the a o o plane to rovide support for a a i t d inwardly facing surface 36 when the tab is positioned blade 18. A relatively narrow radially extending transion the web.

Thus, it will be apparent that the tab 52 and the associated opening 36 cooperate to provide a retaining means for maintaining the clip in assembled relationship with the Web section 26. It will be further evident from the foregoing description that it will generally be necessary to deform the clip to effect its separation from an associated web section.

' Preferably and as shown the clip is positioned on an associated web section with its tab carrying leg 44 radially extending into the channel 30. The other leg 42 which generally closely conforms with the rear or outer surface of the web section 26 has a smooth unbroken surface which exerts a minimal effect upon the noise level and air moving characteristics of an associated fan.

. In most normal fan operating positions each balance clip 20 is wholly concealed from view by an associated fan blade 18 and therefore does not detract from the appearance of the fan.

The invention claimed is:

1. In a fan assembly the combination comprising a fan spider having a central hub portion and a plurality of similar radially extending circurnaxially spaced arm portions, a plurality of fan blades equal in number to said arm portions of said spider and respectively secured to the front sides of said arm portions, each of said arm portions including a Web section rearwardly spaced from an associated one of the said blades and having an opening therein, a balance clip slidably received on at least one of the said web sections and comprising a generally U-shaped member with elongated legs sprung into straddling relationship With the Web section and with its legs in engagement with opposite surfaces thereof, said clip further comprising an integral tab struck from one of the legs and extending angularly into said web section opening so as to engage an outer portion of the wall of the opening and thereby to lock the clip on the Web section, and at least one of said clip legs having an outwardly flared end portion for ease of assembly of the clip on the web section.

2. The combination as set forth in claim 1 wherein each of said elongated legs has an outwardly flared end section.

References Cited by the Examiner UNITED STATES PATENTS 1,897,947 2/1933 Howell. 2,140,017 12/1938 Koch 170-173 2,317,502 4/1943 Upson 170-159 3,147,811 9/1964 Klonoski 170-173 MARTIN P. SCHWADRON, Primary Examiner.

EVERETTE A. POWELL, 1a., Examiner. 

1. IN A FAN ASSEMBLY THE COMBINATION COMPRISING A FAN SPIDER HAVING A CENTRAL HUB PORTION AND A PLURALITY OF SIMILAR RADIALLY EXTENDING CIRCUMAXIALLY SPACED ARM PORTIONS, A PLURALITY OF FAN BLADES EQUAL IN NUMBER TO SAID ARM PORTIONS OF SAID SPIDER AND RESPECTIVELY SECURED TO THE FRONT SIDES OF SAID ARM PORTIONS, EACH OF SAID ARM PORTIONS INCLUDING A WEB SECTION REARWARDLY SPACED FROM AN ASSOCIATED ONE OF THE SAID BLADES AND HAVING AN OPENING THEREIN, A BALANCE CLIP SLIDABLY RECEIVED ON AT LEAST ONE OF THE SAID WEB SECTIONS AND COMPRISING A GENERALLY U-SHAPED MEMBER WITH ELONGATED LEGS SPRUNG INTO STRADDLING RELATIONSHIP WITH THE WEB SECTION AND WITH ITS LEGS IN ENGAGEMENT WITH OPPOSITE SURFACES THEREOF, SAID CLIP FURTHER COMPRISING AN INTEGRAL TAB STRUCK FROM ONE OF THE LEGS AND EXTENDING ANGULARLY INTO SAID WEB SECTION OPENING SO AS TO ENGAGE AN OUTER PORTION OF THE WALL OF THE OPENING AND THEREBY TO LOCK THE CLIP ON THE WEB SECTION, AND AT LEAST ONE OF SAID CLIP LEGS HAVING AN OUTWARDLY FLARED END PORTION FOR EASE OF ASSEMBLY OF THE CLIP ON THE WEB SECTION. 